The Seville Statement
Approved by UNESCO’s General Conference, 25th session, Paris, France, 16 November 1989

Summary (by Christophe Barbey for APRED)

1) We have not inherited war and weapons from animals.
2) War and violence are not genetically programmed in humans. Genetics by itself cannot dictate behavior.
3) Human evolution does not promote aggressive behavior.
4) There isn’t any human physiological compulsion which induces violence. Even when we find ourselves in the most difficult situations, we filter our behavior according to our own choices, the way we socialize and the factors that condition our behaviors.
5) War does not result from instincts, but it is the result of cognitive choices. The very same species that invented war is equally capable of inventing peace : each individual is responsible for this.

Seville Manifesto

The Seville Statement. With a summary

The original version Presently the link does not work and the declaration though often quoted is not found on UNESCO Website

There is a wikipedia page here.